Recently, vehicles such as an electronic vehicle (EV) having a motor driven by an electric power supplied from a battery have spread. The electric vehicle comprises a storage device which comprises both the battery and a battery management unit (BMU) configured to control charging and discharging of the battery. The battery management unit exchanges control information with an electronic control unit (ECU) of the electric vehicle by a control area network (CAN) communication protocol. The CAN communication protocol identifies communication information by a unique identifier called CANID, in the communication area. The BMU therefore executes communication using a unique identifier in the communication area of the electric vehicle.